[dsraven]

thats what I mentioned in an earlier post, the intake gaskets are plastic with a perimeter of silicone set into a groove in the plastic. they leak when the plastic cracks and causes coolant to leak out, but also in, so you may have a slightly chocolate milk look to the engine oil if bad enough. sometimes a small internal leak is hard to detect but you can tell something is going on if you remove the oil filler cal and flip it over. if there is milky crud stuck to the back side of the cap then you have an issue.
I am sure your mechanic buddy will pressure test the system but if that is the only coolant leak found then have the gaskets replaced with a metal sandwich style, felpro makes a good one, and also pull the block drains and flush the block while there to get rid of sediment in the bottom of the block.also an great time to replace the water pimp and/or block heater (if equipped).